Structures are often repaired or reinforced by wrapping them in a composite of high-strength fiber in a polymer matrix. Sheets of textile fabric may be dipped in liquid resin then layered onto or wrapped around a structure. Sometimes panels of cured or partially cured fiber-reinforced plastic (FRP) are prepared in advance, then the panels are glued or mechanically attached to the surface of the structure.
For some applications it is more efficient to pre-fabricate FRP into a repair device with a shape similar to the surface of the structure. At the worksite, the roughly shaped repair device is quickly installed upon the structure. This approach is especially useful for elongate structures such as columns or pilings, and in difficult working conditions where mixing and using liquid resins is impractical.
Pier pilings set in water and extending above it are an example of elongate structures that often need to be repaired or reinforced, yet are difficult to work on. Structures partly under water suffer accelerated damage near the interface of water and air, for both mechanical and chemical reasons. Forces from breaking waves are strongest at the water's surface, boats typically strike a piling near the surface, and exposure to both water, especially sea water, and air drives electrochemical corrosion of metals and rotting of wood. Repairing a piling generally requires working near breaking waves and partially under the water.
Pre-fabricated repair jackets are thus often used to repair or reinforce pilings in marine environments. A jacket is wrapped or otherwise installed on the piling, then grout or epoxy is typically poured into the space between the jacket and the piling to affix the jacket permanently and rigidly to the piling. A problem with this repair method is that it is not always possible to grout the gap immediately after installing the jacket. During the time between installation and grouting, a jacket may be exposed to tides, breaking waves, and boat wakes. Because the ungrouted jacket can shift and rattle on the piling, the jacket can be itself damaged and need replacing before it is grouted.
Conventional repair jackets employ resilient material such as strips of rubber to protect the jacket from buffeting by waves and to form a bottom seal to prevent the grout from leaking out the bottom of the jacket. The rubbery materials used are sometimes torn or dislodged by wave action.
Therefore, there is a need for a repair jacket that is less susceptible to wave damage during the tine between preliminary installation and grouting. There is further a need for a repair jacket that can be easily installed by a worker who remains above the surface of the water. There is a need for a repair jacket with a robust bottom seal that is not torn or deformed by wave or tidal forces.